Sudden and unanticipated cutoffs in the normal supply of electrical energy to facilities such as operation rooms in hospitals and the like can create significant hazards to life and property. Accordingly, such facilities often have a backup battery system which is normally not in use but which is automatically or manually connected in circuit to supply, on an emergency basis, enough electrical energy to such facility to keep it operating during the period when the normal supply of energy is interrupted.
However, backup battery systems, if not suitably monitored, may not function in time of need because of battery failures or other associated problems which have gone undetected during periods of nonuse.
The present invention is directed toward a device, an emergency power monitor, which can be used to monitor the performance of storage batteries at any time while the backup system is not in use and which will generate signals which can be used to operate suitable warning devices when such performance is shown unsuitable.
Many types of emergency power monitors are known in the art. However, an emergency power monitor in accordance with the present invention is characterized by new simple inexpensive circuitry which operates reliably at all times and, moveover, when activiated will produce the requisite signals when the battery output voltage exceeds or falls below predetermined maximum or minimum values and/or when the level of electrolyte in a battery cell falls below a predetermined minimum value.